The purpose of this thesis was to define key elements of the migrant labor system structure by mapping its boundaries. Elements of the social structure in areas where large numbers of potential migrants were found and personal reasons given for joining the migrant stream were examined to understand how the structure is perceived by and motivates the behavior of individuals. It was suggested that certain conditions were more effective in keeping individuals in the stream and that sources of possible changes in these conditions should be foreseen. An examination of the economic elements of the system showed that there are still large areas where manipulation of the structure is possible. A construct called "mobility" was synthesized to provide one possible explanation for variations in the behavior of individuals affected by similar social conditions. Suggestions for further research were provided, along with samples of forms. (PS)